Set apex_available property

The marked library(ies) were available to the APEXes via the
hand-written whitelist in build/soong/apex/apex.go. Trying to remove the
whitelist by adding apex_available property to the Android.bp of the
libraries.

Exempt-From-Owner-Approval: cherry-pick from internal

Bug: 150999716
Test: m
Merged-In: I54db09314c7236a227f04281a439c1d5dc56ef2c
Change-Id: I54db09314c7236a227f04281a439c1d5dc56ef2c
(cherry picked from commit a2606921)